Capital Stock Repurchase Plan Transactions (Schedule Of Capital Stock Repurchases) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Capital Stock Repurchase Plan Transactions [Abstract]
Total cost of repurchased shares	$ 37,672	$ 71,926	$ 121,976
Shares repurchased	120,622	219,009	430,622
Weighted average price per share	$ 312.31	$ 328.41	$ 283.26

Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

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